1. Field of the Invention
The present invention relates to a thermoplastic resin composition comprising a polyphenylene ether resin and a new polystyrene resin.
More particularly, the present invention relates to a thermoplastic resin blended composition having simultaneously excellent mechanical properties, flowability, and appearance for molded articles prepared therefrom.
2. Description of Related Art
Polyphenylene ether resin is a thermoplastic material prepared by various methods from various phenols and has excellent physical properties such as, for example, dimensional stability and dielectric properties.
However, uses of polyphenylene ether resin are restricted due to, for example, inferior processability, impact strength, and solvent stability.
Therefore, blending of polyphenylene ether resin with other polymers has been attempted to improve processability, impact strength and solvent stability.
For example, a resin composition comprising a polyphenylene ether resin and one or more kinds of polystyrene resins is illustrated in U.S. Pat. No. 3,383,435. A resin composition comprising the polyphenylene ether resin and a rubber-modified polystyrene is illustrated in U.S. Pat. No. 3,819,761. However, these resin compositions have insufficient flowability.
A polyphenylene ether resin composition comprising an impact resistant rubber-modified polystyrene and low molecular weight styrene homopolymer (number average molecular weight: 30,000 to 60,000) is illustrated in U.S. Pat. No. 3,960,808. However, although the flowability of the resin composition is improved, the resin still has decreased impact strength.
Furthermore, when the conventional polyphenylene ether resin composition is molded, inferior appearances such as weld lines, flow marks, and break out (stand out) are problematic. It is desired to solve these and other problems in accordance with shortening of the molding cycle and thinning of molded articles produced from these resins.